Display device and method of manufacturing the same

ABSTRACT

A display device and a method of manufacturing a display device are provided. A manufacturing method of a display device includes: forming a display module including a first area defined therein, the display module including a display panel including a lower surface and an upper surface opposite the lower surface, a first film under the lower surface of the display panel, a second film on the upper surface of the display panel, and an adhesive layer between the lower surface of the display panel and the first film; and irradiating a laser beam in an upper direction extending from the lower surface of the display panel to the upper surface of the display panel to cut the first film and the adhesive layer along an edge of the first area, the laser beam provided to the display panel having a laser power equal to or less than about 1 W.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/409,319, filed Jan. 18, 2017, which claims priority to and thebenefit of Korean Patent Application No. 10-2016-0072734, filed on Jun.10, 2016 in the Korean Intellectual Property Office, the entire contentof both of which is incorporated herein by reference.

BACKGROUND

1. Field

The present disclosure relates to a display device and a method ofmanufacturing the same. More particularly, the present disclosurerelates to an organic light emitting display device and a method ofmanufacturing the organic light emitting display device.

2. Description of the Related Art

An organic light emitting display device includes a plurality of pixels.Each pixel includes an organic light emitting diode and a circuit partcontrolling the organic light emitting diode. The circuit part includesat least a control transistor, a driving transistor, and a storagecapacitor.

The organic light emitting diode includes an anode, a cathode, and anorganic light emitting layer disposed between the anode and the cathode.The organic light emitting diode emits a light when a voltage greaterthan a threshold voltage of the organic light emitting layer is appliedbetween the anode and the cathode.

SUMMARY

According to an aspect, the present disclosure provides a display deviceincluding a display module easily bent in a bending area and having asmall radius of curvature by providing a groove overlapped with thebending area in a first film and an adhesive layer.

According to another aspect, the present disclosure provides a method ofmanufacturing a display device, in which a first film and an adhesivelayer may be selectively removed without damaging a base substrate.

According to one or more embodiments of the inventive concept, a methodof manufacturing a display device includes forming a display moduleincluding a first area defined therein, the display module including adisplay panel including a lower surface and an upper surface oppositethe lower surface, a first film under the lower surface of the displaypanel, a second film on the upper surface of the display panel, and anadhesive layer between the lower surface of the display panel and thefirst film and irradiating a laser beam in an upper direction extendingfrom the lower surface of the display panel to the upper surface of thedisplay panel to cut the first film and the adhesive layer along atleast one edge of the first area.

In an embodiment, the laser beam provided to the display panel in thecutting of the first film and the adhesive layer has a laser power equalto or less than about 1 W.

In an embodiment, the laser beam is a CO₂ laser beam or an UV laserbeam.

In an embodiment, the CO₂ laser beam has a wavelength of from about 9.1μm to about 10.7 μm, or the UV laser beam has a wavelength equal to orsmaller than about 360 nm.

In an embodiment, the first area crosses the display module in a firstdirection when viewed in a plan view, and irradiating the laser beam tocut the first film and the adhesive layer includes irradiating the laserbeam to a first edge of the at least one edge of the first areaextending in the first direction and irradiating the laser beam to asecond edge, of the at least one edge of the first area extending in thefirst direction and spaced apart from the first edge of the first area.

In an embodiment, the method further includes bending the display modulewith respect to a reference axis defined in the first area and extendingin the first direction.

In an embodiment, the method further includes irradiating another laserbeam to the first area between the first edge and the second edge to cutthe first film and the adhesive layer.

In an embodiment, a shape of the lower surface of the display panel isnot deformed in the irradiating the laser beam to cut the first film andthe adhesive layer.

In an embodiment, the display panel includes a base substrate definingthe lower surface and including polyimide. In an embodiment, the firstfilm includes polyethylene terephthalate.

In an embodiment, a first portion of a lower surface of a base substrateof the display panel is exposed by the irradiating the laser beam to cutthe first film and the adhesive layer, and the first portion is flat bythe irradiating the laser beam.

In an embodiment, the method further includes removing a portion of thefirst film and a portion of the adhesive layer which are in the firstarea.

According to one or more embodiments of the inventive concept, a displaydevice includes a display panel, a first film, a second film, and anadhesive layer. The display panel includes a lower surface and an uppersurface opposite the lower surface. The first film is under the lowersurface of the display panel and includes a film groove defined therein.The second film is on the upper surface of the display panel. Theadhesive layer is between the lower surface of the display panel and thefirst film and includes an adhesive groove defined therein to overlapwith the first area.

In an embodiment, the display panel includes a base substrate providingthe lower surface and including polyimide.

In an embodiment, a first portion of the base substrate exposed by thefilm groove and the adhesive groove and a second portion of the basesubstrate overlapped with the first film and the adhesive layer have adifference of crystallization degree of about 5%.

In an embodiment, the second portion has a crystallization degreegreater than a crystallization degree of the first portion.

In an embodiment, the first portion of the base substrate is connectedto an inner surface of the adhesive groove.

In an embodiment, a crystallization degree of the first portion issmaller by about 5% than a crystallization degree of a third portionexposed by the film groove and the adhesive groove and spaced apart fromthe second portion by the first portion.

In an embodiment, the second portion has a same crystallization degreeas the third portion.

In an embodiment, a lower surface of the third portion has a surfaceroughness greater than a surface roughness of a lower surface of thefirst portion.

In an embodiment, an angle between the second portion of the basesubstrate and each of an inner surface of the first film providing thefilm groove and an inner surface of the adhesive layer providing theadhesive groove is an acute angle.

In an embodiment, the display device further includes a burr on a lowersurface of the first film adjacent to the film groove.

In an embodiment, the display panel includes a display area to displayan image and a non-display area adjacent to the display area, and thefilm groove and the adhesive groove are in the non-display area.

In an embodiment, the display panel includes a display area to displayan image and a non-display area adjacent to the display area, and thefilm groove and the adhesive groove cross the display area when viewedin a plan view.

In an embodiment, the film groove and the groove cross the display panelin a first direction, and the display device is bent with respect to areference axis defined to overlap with the film groove and the adhesivegroove and extending in the first direction.

In an embodiment, the first film comprises polyethylene terephthalate(PET). The second film includes a polarizing plate.

According to one or more embodiments of the inventive concept, a displaydevice includes a display panel, a first film, a second film, and anadhesive layer. The display panel includes a first area defined thereinand includes a lower surface and an upper surface opposite the lowersurface. The first film is under the lower surface of the display panel.The second film is on the upper surface of the display panel. Theadhesive layer is between the lower surface of the display panel and thefirst film. The display panel includes a base substrate defining thelower surface of the display panel, a plurality of grooves is defined inthe first film and the adhesive layer in the first area to expose thebase substrate, and a first portion of the first film and a firstportion of the adhesive layer are separated from a second portion of thefirst film and a second portion of the adhesive layer by a groove of theplurality of grooves in the first area.

In an embodiment, the base substrate includes polyimide.

In an embodiment, the plurality of grooves includes a first grooveextending in a first direction along a first edge of the first area, asecond groove extending in the first direction along a second edge ofthe first area spaced apart from the first edge, and at least one thirdgroove extending in the first direction between the first edge and thesecond edge.

In an embodiment, the first area is bent with respect to a referenceaxis defined in the first area and extending in the first direction.

According to an aspect, the groove is provided to the first film and theadhesive layer to overlap with the bending area, and thus the displaymodule may be easily bent in the bending area, and the radius ofcurvature of the display module may become small.

According to the manufacturing method of the display device, the firstfilm and the adhesive layer may be selectively removed without damagingthe base substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and advantages of the present disclosurewill become readily apparent by reference to the following detaileddescription when considered in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a flowchart showing a method of manufacturing a display deviceaccording to an exemplary embodiment of the present disclosure;

FIG. 2 is a plan view showing a mother substrate according to anexemplary embodiment of the present disclosure;

FIG. 3 is a plan view showing a display module of FIG. 2;

FIG. 4 is a cross-sectional view taken along a line I-I′ of FIG. 3;

FIG. 5 is a cross-sectional view showing a stacking structure of adisplay panel of FIG. 4;

FIG. 6 is a cross-sectional view showing a portion of a display panelcorresponding to one pixel area;

FIGS. 7 and 8 are cross-sectional views taken along the line I-I′ ofFIG. 3;

FIG. 9 is a photograph showing an experimental subject irradiated with alaser beam exceeding about 1 W;

FIG. 10 is a photograph showing an experimental subject irradiated witha laser beam equal to or less than about 1 W;

FIG. 11 is a graph showing a degree of crystallization of polyimideaccording to a power of a laser beam;

FIG. 12 is a flowchart showing a manufacturing method of a displaydevice according to another exemplary embodiment of the presentdisclosure;

FIG. 13 is a plan view showing a display module illustrating amanufacturing method of a display device according to another exemplaryembodiment of the present disclosure;

FIG. 14 is a cross-sectional view taken along a line II-II′ of FIG. 13;

FIG. 15 is a perspective view showing an organic light emitting displaydevice according to an exemplary embodiment of the present disclosure;

FIG. 16 is a plan view showing the organic light emitting display deviceof FIG. 15;

FIG. 17 is a cross-sectional view taken along a line III-III′ of FIG.16;

FIG. 18 is a cross-sectional view taken along the line III-III′ of FIG.16 when the organic light emitting display device is bent;

FIGS. 19 and 20 are cross-sectional views showing display modulesaccording to exemplary embodiments of the present disclosure;

FIG. 21 is a plan view showing a display module according to anotherexemplary embodiment of the present disclosure;

FIG. 22 is a plan view showing the display module of FIG. 21 in a bentstate;

FIG. 23 is a perspective view showing an organic light emitting displaydevice according to another exemplary embodiment of the presentdisclosure;

FIG. 24 is a plan view showing the organic light emitting display deviceof FIG. 23;

FIG. 25 is a cross-sectional view taken along a line IV-IV′ of FIGS. 24;and

FIG. 26 is a cross-sectional view taken along the line IV-IV′ of FIG. 24when the organic light emitting display device is bent.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of variousembodiments of the present disclosure as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the various embodiments describedherein can be made without departing from the scope and spirit of thepresent disclosure.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to,” or “coupled to” another element or layer, itcan be directly on, connected, or coupled to the other element or layer,or intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present.

Hereinafter, the present invention will be explained in further detailwith reference to the accompanying drawings.

FIG. 1 is a flowchart showing a method of manufacturing a display deviceaccording to an exemplary embodiment of the present disclosure; FIG. 2is a plan view showing a mother substrate according to an exemplaryembodiment of the present disclosure; FIG. 3 is a plan view showing adisplay module of FIG. 2; and FIGS. 4, 7, and 8 are cross-sectionalviews taken along a line I-I′ of FIG. 3.

Referring to FIGS. 1 and 2, a mother substrate 2000 including a displaymodule 1000 is formed (S10).

The mother substrate 2000 includes a plurality of display modules 1000and a dummy part DM. The display modules 1000 are formed using onesubstrate.

In FIG. 2, the mother substrate 2000 including six display modules 1000is shown, but the number of the display modules 1000 is not limited tosix. That is, the number of the display modules 1000 included in onemother substrate 2000 may be greater than or less than six.

The display modules 1000 and the dummy part DM may be flexible.Accordingly the mother substrate 2000 may be flexible.

Each of the display modules 1000 may display an image in response to asignal applied thereto. Each of the display modules 1000 may include anyof various types of display panels, but hereinafter, the display modules1000 including an organic light emitting display panel will bedescribed.

The dummy part DM may be disposed between the display modules 1000. Thedummy part DM may be disposed adjacent to an edge of each of the displaymodules 1000 to surround the display modules 1000. The dummy part DM maybe finally removed in the manufacturing process of the display device.

Hereinafter, directions in which two adjacent sides of the displaymodule 1000 extend are respectively referred to as a first direction DR1and a second direction DR2. In FIG. 2, the first direction DR1corresponds to a direction in which short sides of the display module1000 extend, and the second direction DR2 corresponds to a direction inwhich long sides of the display module 1000 extend. However, the firstdirection DR1 and the second direction DR2 may be changed with respectto each other according to embodiments.

Referring to FIG. 3, the display module 1000 includes a display area DAand a non-display area NA defined therein when viewed in a plan view.The image is displayed through the display area DA and not displayedthrough the non-display area NA. The non-display area NA is disposedadjacent to the display area DA.

In FIG. 3, the non-display area NA is disposed adjacent to one side ofthe display area DA. In one embodiment, the display area DA and thenon-display area NA are disposed adjacent to each other in the seconddirection DR2, but are not limited thereto or thereby. That is, thenon-display area may be further defined adjacent to one or more of theother three sides of the display area DA.

A pad area PDA may be defined in the non-display area NA. The pad areaPDA is connected to a flexible printed circuit board (not shown), andthe display module 1000 receives signals required to drive itselfthrough the pad area PDA.

A first area GRA may be further defined in the non-display area NA. Thefirst area GRA may be defined between the pad area PDA and the displayarea DA and spaced apart from the pad area PDA and the display area DA.The first area GRA may correspond to an area in which a groove isdefined when the organic light emitting display device according to thepresent disclosure is completely manufactured.

The first area GRA crosses the display module 1000 in the firstdirection DR1 when viewed in a plan view. A first edge EG1 and a secondedge EG2 of the first area GRA extend in the first direction DR1 and arespaced apart from each other.

Referring to FIG. 4, the display module 1000 includes a display panel100, a first film 200, a second film 300, and an adhesive layer 400.

The display panel 100 includes a lower surface 101 and an upper surface102. Hereinafter, a direction substantially vertical to the lowersurface 101 or the upper surface 102 of the display panel 100 andextending toward the upper surface 102 from the lower surface 101 of thedisplay panel 100 is referred to as an upper direction DR3.

The first film 200 is disposed under the lower surface 101 of thedisplay panel 100. The second film 300 is disposed above the uppersurface 102 of the display panel 100. The adhesive layer 400 is disposedbetween the lower surface 101 of the display panel 100 and the firstfilm 200.

The first film 200 may protect the display panel 100. The first film 200may include polyethylene terephthalate (PET), polyethylene naphthalate(PEN), polypropylene (PP), polycarbonate (PC), polystyrene (PS),polysulfone (PSul), polyethylene (PE), polyphthalamide (PPA),polyethersulfone (PES), polyarylate (PAR), polycarbonate oxide (PCO), ormodified polythenylene oxide (MPPO). In the present exemplaryembodiment, the first film 200 may include polyethylene terephthalate(PET) as a representative example.

The second film 300 may include a polarizing plate. The polarizing platemay block an external light incident thereto. The polarizing plate mayinclude a linear polarizing layer and a λ/4 retardation layer. Infurther detail, the linear polarizing layer may be disposed on the λ/4retardation layer. The external light sequentially passing through thelinear polarizing layer and the λ/4 retardation layer may be reflectedby a lower portion of the polarizing plate, e.g., a cathode of thedisplay panel 100, and the reflected external light may become extinctsince the reflected external light does not pass through the linearpolarizing layer after passing through the λ/4 retardation layer.

The adhesive layer 400 adheres the display panel 100 to the first film200. The adhesive layer 400 may include a urethane-based material, anacrylic-based material, or a silicon-based material. The adhesive layer400 may be a pressure-sensitive adhesive layer.

FIG. 5 is a cross-sectional view showing a stacking structure of thedisplay panel 100; and FIG. 6 is a cross-sectional view showing aportion of the display panel 100 corresponding to one pixel area. Asshown in FIG. 6, one pixel is disposed in one pixel area PA.

Referring to FIGS. 5 and 6, the display panel 100 includes a basesubstrate 110, a driving layer 120, an organic light emitting elementlayer 130, and a sealing layer 140.

The base substrate 110 provides the lower surface 101 of the displaypanel 100. The base substrate 110 may be, but is not limited to, aflexible substrate and may include a plastic material having superiorthermal resistance and durability, e.g., polyethylene terephthalate(PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate(PAR), polyetherimide (PEI), polyethersulfone (PES), polyimide (PI),etc. The base substrate 110 may include polyimide as a representativeexample.

The driving layer 120 includes devices to apply signals to the organiclight emitting element layer 130. The driving layer 120 includes varioussignal lines, such as a scan line (not shown), a data line (not shown),a power source line (not shown), a light emitting line (not shown), etc.The driving layer 120 includes a plurality of transistors andcapacitors. The transistors include a switching transistor (not shown)and a driving transistor Qd, which are arranged in every one pixel (notshown).

FIG. 6 shows the driving transistor Qd of the driving layer 120 as arepresentative example. The driving transistor Qd includes an activelayer 211, a gate electrode 213, a source electrode 215, and a drainelectrode 217.

The active layer 211 is disposed on the base substrate 110. The drivinglayer 120 further includes a first insulating layer 221 disposed betweenthe active layer 211 and the gate electrode 213. The first insulatinglayer 221 insulates the active layer 211 from the gate electrode 213.The source electrode 215 and the drain electrode 217 are disposed on thegate electrode 213. The driving layer 120 further includes a secondinsulating layer 223 disposed between the gate electrode 213 and thesource electrode 215 and between the gate electrode 213 and the drainelectrode 217. The source electrode 215 and the drain electrode 217 areconnected to the active layer 211 respectively through contact holes CH1and CH2 formed through the first insulating layer 221 and the secondinsulating layer 223.

The driving layer 120 further includes a protective layer 230 disposedon the source electrode 215 and the drain electrode 217.

The present disclosure is not limited to the structure of the drivingtransistor Qd shown in FIG. 6, and positions of the active layer 211,the gate electrode 213, the source electrode 215, and the drainelectrode 217 may be changed in various ways. For instance, the gateelectrode 213 is disposed on the active layer as shown in FIG. 6, butthe gate electrode 213 may be disposed under the active layer 211according to embodiments.

Although a structure of the switching transistor is not shown in FIG. 6,but the switching transistor (not shown) may have substantially the samestructure as that of the driving transistor Qd. However, the switchingtransistor may have a structure different from that of the drivingtransistor Qd according to embodiments. For instance, an active layer(not shown) of the switching transistor (not shown) may be disposed on alayer different from a layer on which the active layer 211 of thedriving transistor Qd is disposed.

The organic light emitting element layer 130 may include an organiclight emitting diode LD. In the present exemplary embodiment, theorganic light emitting diode LD may be a front surface light emittingtype organic light emitting diode LD, and thus the organic lightemitting diode LD may emit a light to the upper direction DR3.

The organic light emitting diode LD includes a first electrode AE, anorganic layer OL, and a second electrode CE.

The first electrode AE is disposed on the protective layer 230. Thefirst electrode AE is connected to the drain electrode 217 through acontact hole CH3 formed through the protective layer 230.

The first electrode AE may be a pixel electrode or a positive electrode.The first electrode AE may be a transflective electrode or a reflectiveelectrode. In the case where the first electrode AE is the transflectiveelectrode or the reflective electrode, the first electrode AE mayinclude Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a mixture thereof.

The first electrode AE has a single-layer structure of a metal oxide ora metal or has a multi-layer structure of layers. For instance, thefirst electrode AE may have a single-layer structure of ITO, Ag, or amixture of metal, e.g., a mixture of Ag and Mg, a double-layer structureof ITO/Mg or ITO/MgF, or a triple-layer structure of ITO/Ag/ITO, but isnot limited thereto or thereby.

The organic layer OL may include an organic light emitting layercontaining a low molecular weight or high molecular weight organicmaterial. The organic light emitting layer may emit the light. Theorganic layer OL may selectively include a hole transport layer, a holeinjection layer, an electron transport layer, and an electron injectionlayer in addition to the organic light emitting layer.

Holes and electrons are injected into the organic light emitting layerof the organic layer OL from the first electrode AE and the secondelectrode CE, and the holes are recombined with the electrons in theorganic light emitting layer to generate excitons. The excitons emitenergy discharged when an excited state returns to a ground state aslight.

The second electrode CE is disposed on the organic layer OL. The secondelectrode CE may be a common electrode or a negative electrode. Thesecond electrode CE may be a transmissive electrode or a transflectiveelectrode. In the case where the second electrode CE is the transmissiveelectrode or the transflective electrode, the second electrode CE mayinclude Li, Ca, LiF/Ca, LiF/AI, AI, Mg, BaF, Ba, Ag, a compound thereof,or a mixture thereof, e.g., a mixture of Ag and Mg.

The second electrode CE may include an auxiliary electrode. Theauxiliary electrode may include indium tin oxide (ITO), indium zincoxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), Mo, Ti, Ag,etc.

The organic light emitting element layer 130 may further include a pixeldefinition layer PDL disposed on the protective layer 230. The pixeldefinition layer PDL may be disposed to overlap with a boundary of thepixel area PA when viewed in a plan view.

The sealing layer 140 is disposed above the organic light emittingelement layer 130. The sealing layer 140 provides the upper surface 102of the display panel 100. The sealing layer 140 blocks the organic lightemitting element layer 130 from external moisture and oxygen. Thesealing layer 140 includes a sealing substrate 141 and a sealing member(not shown). The sealing member (not shown) is disposed along an edge ofthe sealing substrate 141 and seals the organic light emitting diode LDtogether with the sealing substrate 141. An inner space 143 defined bythe sealing substrate 141 and the sealing member (not shown) ismaintained in a vacuum state. However, the inner space 143 may be filledwith nitrogen (N₂) or with a filling member of an insulating material.

Different from the display panel 100 shown in FIG. 6, the sealing layer140 may have a structure in which an organic layer and an inorganiclayer are stacked multiple times.

Referring to FIGS. 1, 3, 4, and 7, the first film 200 and the adhesivelayer 400 are cut along an edge of the first area GRA (S20).

In the cutting of the first film 200 and the adhesive layer 400 (S20), alaser beam is irradiated in the upper direction DR3 from the lower sideof the display module 1000 to cut the first film 200 and the adhesivelayer 400.

The laser beam may be irradiated using a CO₂ laser source having a highenergy efficiency or the UV laser source. In an embodiment, the laserbeam emitted from the CO₂ laser source has a wavelength from about 9.1μm to about 10.7 μm. In an embodiment, the laser beam emitted from theUV laser source has a wavelength equal to or smaller than about 360 nm.

The cutting of the first film 200 and the adhesive layer 400 (S20) mayinclude irradiating a laser beam LZ1 along the first edge EG1 of thefirst area GRA and irradiating a laser beam LZ2 along the second edgeEG2 of the first area GRA.

After the cutting of the first film 200 and the adhesive layer 400(S20), a first groove G1 is formed in the first film 200 and theadhesive layer 400 to overlap with the first edge EG1 of the first areaGRA, and a second groove G2 is formed in the first film 200 and theadhesive layer 400 to overlap with the second edge EG2 of the first areaGRA.

Each of the first groove G1 and the second groove G2 may have a shapehaving a width which gradually decreases upward along the upperdirection DR3, and an inner surface GS1 of the first groove G1 and aninner surface GS2 of the second groove G2 may be inclined.

Since the laser beams LZ1 and LZ2 are irradiated in the cutting of thefirst film 200 and the adhesive layer 400 (S20), a burr BR is formed onthe lower surface of the first film 200 to be adjacent to the first andsecond grooves G1 and G2. The burr BR may be formed by a portion of thefirst film 200, which is melted by heat energy of the laser beams LZ1and LZ2.

In the cutting of the first film 200 and the adhesive layer 400 (S20), apower of each of the laser beams LZ1 and LZ2 may be equal to or smallerthan about 1 W. When the power of each of the laser beams LZ1 and LZ2 isequal to or smaller than about 1 W, the lower surface 101 of the displaypanel 100 may not be damaged, and the shape of the lower surface 101 ofthe display panel 100 may not be deformed.

Since the first and second grooves G1 and G2 are formed, a first portion11 of the lower surface 101 of the base substrate 110 is exposed. Inaddition, since the first portion 11 of the lower surface 101 of thebase substrate 110 is not physically damaged by the laser beamirradiated thereto, the first portion 11 of the lower surface 101 of thebase substrate 110 may be flat. A second portion 12 of the lower surface101 of the base substrate 110 that is between the first and secondgrooves G1 and G2 may be flat.

The first edge EG1 and the second edge EG2 may be defined in the firstportion 11 of the lower surface 101 of the base substrate 110.

Although not shown in the figures, an adhesive force of the adhesivelayer 400 disposed in the first area GRA may be weakened prior to orafter the cutting of the first film 200 and the adhesive layer 400(S20). The adhesive force of the adhesive layer 400 disposed in thefirst area GRA may be weakened by irradiating an ultraviolet ray to thefirst area GRA.

Referring to FIGS. 1, 4, and 8, the portion of the first film 200 andthe portion of the adhesive layer 400, which are disposed in the firstarea GRA, are removed (S30).

Due to the removal of the portion of the first film 200 and the portionof the adhesive layer 400 (S30), the groove GR is formed. A thirdportion 13 of the lower surface 101 of the base substrate 110, which isexposed through the groove GR, may have an area greater than that of thefirst area GRA.

According to the manufacturing method of the display device of thepresent exemplary embodiment, the adhesive layer 400 and the first film200 are formed on the entire surface of the display panel 100, and thenthe portion of the adhesive layer 400 and the portion of the first film200, which are disposed in a target area, may be easily removed.According to the manufacturing method of the display device of thepresent exemplary embodiment, a manufacturing process may be simplifiedand a manufacturing cost may be reduced when compared with those of amanufacturing method of attaching a first film, from which a portionthereof corresponding to a target area is removed, to the display panel100.

FIG. 9 is a photograph showing an experimental subject irradiated with alaser beam exceeding about 1 W; and FIG. 10 is a photograph showing anexperimental subject irradiated with a laser beam equal to or smallerthan about 1 W. FIGS. 9 and 10 are top views of the experimentalsubject.

In FIGS. 9 and 10, the experimental subject was configured to include afirst member 30 including polyimide (PI) and a second member 40including polyethylene terephthalate (PET). The laser beam wasirradiated to a laser irradiation area LRA along a horizontal directionDRH.

Referring to FIG. 9, the first member 30 and the second member 40 werephysically processed in the laser irradiation area LRA. Referring toFIG. 10, the second member 40 was physically processed in the laserirradiation area LRA, and the first member 30 was not physicallyprocessed in the laser irradiation area LRA.

Referring to FIGS. 7, 9, and 10, in a case in which the adhesive layer400 has a thickness of about 10 pm, it is difficult to precisely cutonly the adhesive layer 400 when considering a depth margin controlledby the laser source. According to the present exemplary embodiment, inthe case in which the power of the laser beam applied to the polyimideis equal to or smaller than about 1 W, the polyimide is not physicallyprocessed. Accordingly, the first film 200 and the adhesive layer 400(e.g., a pressure-sensitive adhesive layer) may be selectively removedwithout damaging the base substrate 110.

Then, the display modules 1000 may be separated from the mothersubstrate 2000 by removing the dummy part DM from the mother substrate2000, but is not limited thereto or thereby. That is, the separation ofthe display modules 1000 from the mother substrate 2000 may be performedprior to the cutting process of the first film and the adhesive layer(S20) and the removing the portion of the first film and the portion ofthe adhesive layer (S30).

In an embodiment, the display module 1000 is bent with respect to areference axis defined in the first area GRA and extending in the firstdirection DR1. The display module 1000 may be bent such that two partsof the first film 200, which are separated by the groove GR, are closerto each other.

FIG. 11 is a graph showing a degree of crystallization (hereinafter,referred to as “crystallization degree”) of polyimide according to apower of a laser beam.

In FIG. 11, “ref” indicates a reference condition when the laser beam isnot irradiated to polyimide, and the crystallization degree in thereference condition was set to 100%. Laser irradiation was performedthree times with each laser power of about 0.3 W, about 0.36 W, about0.42 W, about 0.48 W, about 0.54 W, and about 0.6 W. The laser power wascontrolled by sequentially increasing a repetition rate of the lasersource without changing a spot size of the laser beam.

Referring to FIG. 11, even though the laser power was increased, thecrystallization degree of polyimide was maintained at about 95% or moreof the reference condition. In addition, in the case where the laserbeam was irradiated three times at the same laser power, thecrystallization degree of polyimide was maintained at about 95% or moreof the reference condition. In addition, in the case that the laser beamis irradiated, the crystallization degree of polyimide was lower byabout 5% than the reference condition.

Referring to FIGS. 9 to 11, although the laser beam at a specific laserpower is irradiated to polyimide, polyimide is not physically processed,but the degree of crystallization of polyimide may be varied by about5%.

FIG. 12 is a flowchart showing a manufacturing method of a displaydevice according to another exemplary embodiment of the presentdisclosure; FIG. 13 is a plan view showing a display module illustratinga manufacturing method of a display device according to anotherexemplary embodiment of the present disclosure; and FIG. 14 is across-sectional view taken along a line II-II′ of FIG. 13.

Referring to FIG. 12, operation (S11) is substantially the same as theforming process (S10) described with reference to FIGS. 1 and 2, andthus further details thereof will be omitted.

Referring to FIGS. 12 to 14, the cutting of the first film and theadhesive layer (S21) may include irradiating a laser beam LZ11 along thefirst edge EG1 of the first area GRA, irradiating laser beams LZ12 andLZ13 to the first area GRA along imaginary lines AG1 and AG2substantially parallel to the first edge EG1 at least once, andirradiating a laser beam LZ14 along the second edge EG2 of the firstarea GRA.

In FIGS. 13 and 14, the laser beams LZ12 and LZ13 are irradiated alongthe two imaginary lines AG1 and AG2 in the first area GRA, but thenumber of the imaginary lines is not limited to two. For example, thelaser beam may be irradiated along three or more imaginary lines.

In the cutting of the first film and the adhesive layer (S21), the laserpower of each of the laser beams LZ11, LZ12, LZ13, and LZ14 provided tothe base substrate 110 may be equal to or smaller than about 1 W.

After the cutting of the first film and the adhesive layer (S21), afirst groove G11 is formed in the first film 200 and the adhesive layer400 to overlap with the first edge EG1 of the first area GRA, a secondgroove G12 is formed in the first film 200 and the adhesive layer 400 tooverlap with the first imaginary line AG1, a third groove G13 is formedin the first film 200 and the adhesive layer 400 to overlap with thesecond imaginary line AG2, and a fourth groove G14 is formed in thefirst film 200 and the adhesive layer 400 to overlap with the secondedge EG2 of the first area GRA.

Each of the first to fourth grooves G11 to G14 may have a shape having awidth which gradually decreases upward along the upper direction DR3.

Different from the manufacturing method of the display device describedwith reference to FIG. 1, the manufacturing method of the display devicedoes not include the removing of the portion of the first film 200 andthe portion of the adhesive layer 400 disposed in the first area GRA.

In a display module 1001 shown in FIGS. 13 and 14, a first portion 201of the first film 200 and a first portion 401 of the adhesive layer 400may be disposed between the first and second grooves G11 and G12. Inaddition, a second portion 202 of the first film 200 and a secondportion 402 of the adhesive layer 400 may be disposed between the secondand third grooves G12 and G13. Further, a third portion 203 of the firstfilm 200 and a third portion 403 of the adhesive layer 400 may bedisposed between the third and fourth grooves G13 and G14.

The first portion 201 of the first film 200 and the first portion 401 ofthe adhesive layer 400 may be separated from the second portion 202 ofthe first film 200 and the second portion 402 of the adhesive layer 400by the second groove G12. The second portion 202 of the first film 200and the second portion 402 of the adhesive layer 400 may be separatedfrom the third portion 203 of the first film 200 and the third portion403 of the adhesive layer 400 by the third groove G13.

According to the manufacturing method of the display device describedwith reference to FIGS. 12 to 14, although the portion of the first film200 and the portion of the adhesive layer 400 disposed in the first areaGRA are not removed, the display module 1001 may be easily bent in thefirst area GRA since the grooves G11 to G14 are formed.

However, the structure of the display device manufactured by the methodshown in FIG. 12 is not limited to the structure of the display deviceshown in FIG. 14. In the cutting of the first film and the adhesivelayer (S21), the laser beam irradiated along three or more imaginarylines in the first area GRA, and thus the portion of the first film 200and the portion of the adhesive layer 400, which are disposed in thefirst area GRA, may be completely removed. That is, since the groovesoverlapped with the first film 200 and the adhesive layer 400 are formedin the first area GRA, the portion of the first film 200 and the portionof the adhesive layer 400, which are disposed in the first area GRA, maybe completely removed without performing a separate additional process.

FIG. 15 is a perspective view showing an organic light emitting displaydevice according to an exemplary embodiment of the present disclosure;FIG. 16 is a plan view showing the organic light emitting display deviceof FIG. 15; FIG. 17 is a cross-sectional view taken along a line of FIG.16; and FIG. 18 is a cross-sectional view taken along the line III-III′of FIG. 16 when the organic light emitting display device is bent.

Referring to FIGS. 15 to 18, an organic light emitting display device DPincludes the display module 1000, a flexible printed circuit board FPC,and a printed circuit board PCB.

The flexible printed circuit board FPC includes a flexible wiring board122 and a driving circuit chip 125. The driving circuit chip 125 iselectrically connected to wirings of the flexible wiring board 122.

In the case where the flexible printed circuit board FPC includes thedriving circuit chip 125, data pads electrically connected to data linesand control signal pads electrically connected to control signal linesare arranged in a pad area (not shown) of the display panel 100. Thedata lines are connected to transistors arranged in the pixel, and thecontrol signal lines are connected to a scan driving circuit. In thepresent exemplary embodiment, the flexible printed circuit board FPC isprovided in a chip-on-film package, but is not limited thereto orthereby. According to another embodiment, the driving circuit chip 125may be mounted on the non-display area NA of the display panel 100, andthe flexible printed circuit board FPC may be a flexible wiring board.

The printed circuit board PCB is electrically connected to the displaypanel 100 through the flexible wiring board 122 to transmit and receivesignals to and from the driving circuit chip 125. The printed circuitboard PCB provides at least one of image data, a control signal, and apower source voltage to the display panel 100 or the flexible printedcircuit board FPC. The printed circuit board PCB may include activeelements and passive elements. The printed circuit board PCB may includea pad part (not shown) connected to the flexible printed circuit boardFPC.

The display module 1000 displays the image to the upper direction DR3.

The display module 1000 has a structure formed by the manufacturingmethod of the organic light emitting display device according toembodiments of the present disclosure. Herein, the display module 1000will be described in further detail, and the same descriptions as thoseof FIGS. 1 to 8 will not be reiterated.

The display module 1000 may be bent with respect to a reference axis AXextending in the first direction DR1. The reference axis AX may bedefined under the display module 1000. The display module 1000 may bebent such that two parts of the first film 200, which are divided by thegroove GR, are closer to each other.

The display module 1000 may be bent in the first area GRA. A bendingarea BA may be defined in the display module 1000. The display module1000 may be flat in an area other than the bending area BA. The bendingarea BA may have a width smaller than that of the first area GRA.

Since the adhesive layer 400 and the first film 200 have resilience whenthe adhesive layer 400 and the first film 200 are bent and the displaymodule 1000 requires more force to maintain the bent state as athickness of the display module 1000 increases, removing the adhesivelayer 400 and the first film 200 in the bending area BA facilitatesbending the display module 1000. According to the display device of thepresent exemplary embodiment, the groove GR is provided to the firstfilm 200 and the adhesive layer 400 to overlap with the bending area BA,and thus the display module 1000 may be easily bent in the bending areaBA, and a radius of curvature of the display module 1000 becomes smallin the bending area BA.

FIGS. 19 and 20 are cross-sectional views showing display modulesaccording to exemplary embodiments of the present disclosure.

A display module 1002 may include the display panel 100, the first film200, the second film 300, and the adhesive layer 400. A film groove GR1may be defined in the first film 200 to overlap with the first area GRA.A groove GR2 may be defined in the adhesive layer 400 to overlap withthe first area GRA.

A base substrate 110 may include a first part 111, a second part 112,and a third part 113. The first part 111 is exposed by the film grooveGR1 and the adhesive groove GR2 and connected to an inner surface 401 ofthe adhesive groove GR2. The second part 112 is overlapped with thefirst film 200 and the adhesive layer 400. The third part 113 is exposedby the film groove GR1 and the adhesive groove GR2 and spaced apart fromthe second part 112 by the first part 111.

The first part 111 may be a part of the base substrate 110 to which thelaser beams LZ1 and LZ2 are irradiated in the cutting of the first filmand the adhesive layer (S20) described with reference to FIGS. 1 and 7.The second and third parts 112 and 113 may be parts of the basesubstrate 110 to which the laser beams LZ1 and LZ2 are not irradiated inthe cutting of the first film and the adhesive layer (S20) describedwith reference to FIGS. 1 and 7.

The first part 111 of the base substrate 110 may have a difference inthe degree of crystallization of about 5% when compared to that of eachof the second and third parts 112 and 113. In further detail, the firstpart 111 of the base substrate 110 has a relatively smallcrystallization degree within about 5% when compared to that of each ofthe second and third parts 112 and 113. The second and third parts 112and 113 may have substantially the same crystallization degree.

An inner surface 201 of the first film 200 providing the film groove GR1may be connected to the inner surface 401 of the adhesive layer 400providing the groove GR2. As shown in FIG. 19, the inner surface 201 ofthe first film 200 and the inner surface 401 of the adhesive layer 400may have a straight line shape, but may have a curved shape according toother embodiments.

An angle (θ) between the lower surface of the second part 112 of thebase substrate 110 (e.g., a lower surface of the display panel) and eachof the inner surface 201 of the first film 200 and the inner surface 401of the adhesive layer 400 may be an acute angle. This is because thecutting of the first film and the adhesive layer (S20) is performed byirradiating the laser beam to the upper direction DR3.

The display module 1002 may include the burr BR disposed on the lowersurface of the first film 200 adjacent to the film groove GR1. The burrBR may be formed through the cutting of the first film and the adhesivelayer (S20).

According to a display module 1003 shown in FIG. 20, a lower surface ofthe first part 111 of the base substrate 110 may have a surfaceroughness smaller than a surface roughness of the lower surface of thethird part 113 of the base substrate 110.

The lower surface of the first part 111 is formed in the cutting of thefirst film 200 and the adhesive layer 400 (S20) described with referenceto FIGS. 1 and 7, and the lower surface of the third part 113 is formedin the removing of the portion of the first film 200 and the portion ofthe adhesive layer 400 (S30) described with reference to FIGS. 1 and 8.In the removing of the portion of the first film 200 and the portion ofthe adhesive layer 400 (S30), the surface roughness of the lower surfaceof the third part 113 of the base substrate 110 may increase while theadhesive layer 400 is removed from the base substrate 100.

FIG. 21 is a plan view showing a display module according to anotherexemplary embodiment of the present disclosure; and FIG. 22 is a planview showing the display module of FIG. 21 in a bent state.

Referring to FIG. 21, a display module 1004 may include a display areaDA and a non-display area NA defined therein. The non-display area NAsurrounds the display area DA. The non-display area NA may include firstto fourth areas GRA1 to GRA4 defined therein.

The display module 1004 may have substantially the same layer structureas one of the display modules 1001 to 1003 described with reference toFIGS. 14, 19, and 20.

The cutting operation (S20) and the removing operation (S30) shown inFIG. 1 may be performed on the first to fourth areas GRA1 to GRA4.Accordingly, the display module 1004 may have a shape in which the firstfilm 200 and the adhesive layer 400 are removed from the first to fourthareas GRA1 to GRA4.

First to fourth cutting lines CL1 to CL4 are provided to the displaymodule 1004. The display module 1004 may be cut along the first tofourth cutting lines CL1 to CL4.

Referring to FIGS. 21 and 22, the display module 1004 may be bent withrespect to a line extending in the first direction DR1 in each of thefirst and second areas GRA1 and GRA2. In addition, the display module1004 may be bent with respect to a line extending in the seconddirection DR2 in each of the third and fourth areas GRA3 and GRA4.

According to the display module 1004 shown in FIGS. 21 and 22, the firstfilm 200 and the adhesive layer 400 are removed from the first to fourthareas GRA1 to GRA4 defined respectively along four sides of the displaymodule 1004, and the display module 1004 is bent along the four sides,but is not limited thereto or thereby. For example, the first film 200and the adhesive layer 400 may be removed from two or three sides of thedisplay module 1004, and the display module 1004 may be bent along twoor three sides.

FIG. 23 is a perspective view showing an organic light emitting displaydevice according to another exemplary embodiment of the presentdisclosure; FIG. 24 is a plan view showing the organic light emittingdisplay device of FIG. 23; FIG. 25 is a cross-sectional view taken alonga line IV-IV′ of FIG. 24; and FIG. 26 is a cross-sectional view takenalong the line IV-IV′ of FIG. 24 when the organic light emitting displaydevice is bent.

An organic light emitting display device DP1 shown in FIGS. 23 to 26 mayhave the same structure and function as those of the organic lightemitting display device DP described with reference to FIGS. 15 to 18except for a position of a first area, i.e., a position of a groove.

The organic light emitting display device DP1 may include a displaymodule 1100. The display module 1100 may include a display area DA and anon-display area NA defined therein. The display module 1100 may includea first area GRR defined therein.

The first area GRR may be overlapped with the display area DA. The firstarea GRR may be defined to cross the display area DA. The adhesive layer400 (e.g., a pressure-sensitive adhesive layer) and the first film 200,which are overlapped with the first area GRR, may be removed. That is, agroove GRX overlapped with the first area GRR may be provided in thefirst film 200 and the adhesive layer 400.

The display module 1100 may be bent with respect to a reference axis AX1extending in the first direction DR1. The reference axis AX1 may bedefined under the display module 1100. The display module 1100 may bebent such that two parts of the first film 200, which are divided by thegroove GRX, are closer to each other.

The display module 1100 may be bent in the first area GRR. A bendingarea BA1 may be defined in the display module 1100. The display module1100 may be flat in an area other than the bending area BA1. The bendingarea BA1 may have a width smaller than a width of the first area GRR. Asdescribed above, since the groove GRX overlapped with the bending areaBA1 is provided in the first film 200 and the adhesive layer 400, thedisplay module 1100 may be easily bent in the bending area BA1, and theradius of curvature of the display module 1100 may become small.

Although some exemplary embodiments of the present invention have beendescribed, it is to be understood that the present invention is notlimited to these exemplary embodiments, but various changes andmodifications can be made by one of ordinary skill in the art within thespirit and scope of the present invention as claimed herein.

What is claimed is:
 1. A method of manufacturing a display device, themethod comprising: forming a display module including a first areadefined therein, the display module comprising a display panel includinga lower surface and an upper surface opposite the lower surface, a firstfilm under the lower surface of the display panel, and an adhesive layerbetween the lower surface of the display panel and the first film; andirradiating a laser beam in an upper direction extending from the lowersurface of the display panel to the upper surface of the display panelto cut the first film to define a film groove therein and the adhesivelayer to define an adhesive groove therein to overlap with the filmgroove along at least one edge of the first area, wherein the displaypanel comprises a base substrate defining the lower surface, and a firstportion of the base substrate exposed by the film groove and theadhesive groove and a second portion of the base substrate overlappedwith the first film and the adhesive layer have a difference ofcrystallization degree equal to or smaller than about 5%.
 2. The methodof claim 1, wherein the laser beam is a CO₂ laser beam or an UV laserbeam.
 3. The method of claim 2, wherein the CO₂ laser beam has awavelength of from about 9.1 μm to about 10.7 μm, or the UV laser beamhas a wavelength equal to or smaller than about 360 nm.
 4. The method ofclaim 1, wherein the first area crosses the display module in a firstdirection when viewed in a plan view, and the irradiating the laser beamto cut the first film and the adhesive layer comprises: irradiating thelaser beam to a first edge of the at least one edge of the first areaextending in the first direction; and irradiating the laser beam to asecond edge of the at least one edge of the first area extending in thefirst direction and spaced apart from the first edge of the first area.5. The method of claim 4, further comprising bending the display modulewith respect to a reference axis defined in the first area and extendingin the first direction.
 6. The method of claim 4, further comprisingirradiating another laser beam to the first area between the first edgeand the second edge to cut the first film and the adhesive layer.
 7. Themethod of claim 1, wherein the base substrate comprises polyimide. 8.The method of claim 1, wherein the first film comprises polyethyleneterephthalate.
 9. The method of claim 1, wherein a first portion of alower surface of the base substrate of the display panel is exposed bythe irradiating the laser beam to cut the first film and the adhesivelayer.
 10. The method of claim 1, further comprising removing a portionof the first film and a portion of the adhesive layer which are in thefirst area.
 11. A display device comprising: a display panel comprisinga lower surface and an upper surface opposite the lower surface; a firstfilm under the lower surface of the display panel and comprising a filmgroove defined therein; and an adhesive layer between the lower surfaceof the display panel and the first film and comprising an adhesivegroove defined therein to overlap with the film groove, wherein thedisplay panel comprises a base substrate defining the lower surface,wherein the base substrate comprises a first portion and a secondportion, the first portion is exposed by the film groove and theadhesive groove, the second portion is overlapped with the first filmand the adhesive layer, and the first portion and the second portionhave a difference of crystallization degree equal to or smaller thanabout 5%.
 12. The display device of claim 11, wherein the second portionhas a crystallization degree greater than a crystallization degree ofthe first portion.
 13. The display device of claim 11, wherein the firstportion of the base substrate is connected to an inner surface of theadhesive groove, and the first portion has a crystallization degreesmaller by about 5% than a crystallization degree of a third portionexposed by the film groove and the adhesive groove and spaced apart fromthe second portion by the first portion.
 14. The display device of claim13, wherein a lower surface of the third portion has a surface roughnessgreater than a surface roughness of a lower surface of the firstportion.
 15. The display device of claim 11, wherein an angle betweenthe second portion of the base substrate and an inner surface of thefirst film providing the film groove is an acute angle, and wherein anangle between the second portion of the base substrate and an innersurface of the adhesive layer providing the adhesive groove is an acuteangle.
 16. The display device of claim 11, further comprising a burr ona lower surface of the first film adjacent to the film groove.
 17. Thedisplay device of claim 11, wherein the display panel comprises adisplay area to display an image and a non-display area adjacent to thedisplay area, and the film groove and the adhesive groove are in thenon-display area.
 18. The display device of claim 11, wherein thedisplay panel comprises a display area to display an image and anon-display area adjacent to the display area, and the film groove andthe adhesive groove cross the display area when viewed in a plan view.19. The display device of claim 11, wherein the film groove and theadhesive groove cross the display panel in a first direction, and thedisplay device is bent with respect to a reference axis defined tooverlap with the film groove and the adhesive groove and extending inthe first direction.
 20. The display device of claim 11, wherein thebase substrate comprises polyimide.
 21. The display device of claim 11,wherein the first film comprises polyethylene terephthalate (PET).
 22. Adisplay device comprising: a display panel comprising a lower surfaceand an upper surface opposite the lower surface; a first film under thelower surface of the display panel and comprising a film groove definedtherein; and an adhesive layer between the lower surface of the displaypanel and the first film and comprising an adhesive groove definedtherein to overlap with the film groove, wherein the display panelcomprises a base substrate defining the lower surface, wherein the basesubstrate comprises a first portion, a second portion, and a thirdportion, the first portion is exposed by the film groove and theadhesive groove, the second portion is overlapped with the first filmand the adhesive layer, the third portion is exposed by the film grooveand the adhesive groove and spaced apart from the second portion by thefirst portion, a lower surface of the third portion has a surfaceroughness greater than a surface roughness of a lower surface of thefirst portion.